08-16-2008, 02:21 PM #1
Stumped...'03 GPR1300 Power Valves Won't Cycle
Thanks Water Woody and WFO for helping up to this point...
I installed rebuilt motor for '03 GPR1300
Took it out for break-in. Ran very good, but the engine warning light would come on every 10 minutes or less. Would turn off motor, restart, ride, and everything is fine, until 10 minutes later, when engine warning comes back on.
Self-diagnostic button showed two codes: 48 (incorrect data transmission) and 64 (YPVS servomotor malfunction). On dry land I would start and kill the motor, and I noticed that the power valves would not cycle. Instead, you could hear the servo motor struggling (a groaning sound) and you could see that it was TRYING to cycle but would only click back and forth an 1/8" or so (see video).
I replaced the servo motor. This did not fix the problem.
Removed cables from the power valve mounting wheel and did the start/kill routine. Under these circumstances, the cables cycled back and forth twice, as they should (open/close/open/close). (See video)
I've tried everything on these cables: adjusting the tension, switching the cables around (in case they were mixed up), check the cables for frays (no problems--they glide smoothly, no kinks), etc.
Here's what's strange. Per the service manual, I made sure and calibrate the power valve cable mounting wheel so that the hole in the wheel lines up perfect with the hole on the cylinder head. When I placed a 4mm pin into these two holes, I physically could not get them to line up perfectly. They were very close, but the mounting wheel seemed like it needed to rotate clockwise another 1/8" - 3/16" (see the photo--you'll notice that the alignment pin is cock-eyed). Problem is, this wheel will not rotate any further than it is...it's rotated as far clockwise as it can.
Is it possilbe that the remanufactured power valve mounting wheel was improperly set to the shaft it connects to? Is this even possible?
BTW, yes--I've checked all grounds, connectons, etc.
Could a faulty CDI be sending a bad signal to the servo at shut down?
Anything would help! Thanks
Last edited by handybuilder; 08-16-2008 at 05:13 PM.
08-16-2008, 04:36 PM #2
i just went through this. can you take the cables off the wheel and turn the pvs all the way open and closed by hand turning the wheel? Call me if you like. 5027977419
08-16-2008, 07:19 PM #3
This sounds like a mechaincal issue with the power valves themselves. I would disconnect the linkage between all them and try cycling them by hand. might even need to open up the caps for some inspection. the fact the wheel will not home tells me there is an obstruction or assembly error. Who did the rebuild?
08-16-2008, 08:06 PM #4
The rebuild is an SBT. I've heard they have a somewhat dubious track record.
The only issue is if opening the valve covers voids the warranty from them.
The covers seem glued in place. Can I smack 'em with a rubber mallet?
Last edited by handybuilder; 08-17-2008 at 06:30 PM.
08-16-2008, 09:07 PM #5
Send Raider GPR a pm he lives in West Sac, he can give you a hand with this. if you have all the screws out yeah a gentle nudge wont hurt it. I wonder why they seal them. OEM gaskets are metal and reusable.
08-17-2008, 06:32 PM #6
I'll proceed with inspecting the valves when I find out about the warranty issue. In the meantime, anybody else out there dealt with this before? C'mon...suggestions? Faulty CDI? Cables too tight?
08-17-2008, 06:59 PM #7
- Join Date
- Jul 2007
- Pontoon Beach Illinois
08-17-2008, 08:30 PM #8
08-19-2008, 07:23 PM #9
I got the valves to cycle, finally.
I decided to try once more adjusting the cables for position and tightness. Basically, I kept loosening the cables more and more until--finally--everything started working.
As it stands, the valves cycle at shut down, and the valves open properly at high rpm's.
What bothers me is that my cables are pretty loose. The proper tightness is about 1/16" of play. But my cables have about 1/4" or more of play.
I'll take it out and test on the lake and see what happens. I'm hoping that having a loose cable won't affect how far open that valves are at WOT. But then again, I've read here that the valves opening only affects RPM by a matter of a few hundred RPM's, which to me--a pretty recreational rider--does not matter.
Just a note--I have not openied the valves to inspect yet. I'm hoping I won't need to.
08-19-2008, 08:08 PM #10
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